Furnace.



T. A. MARSH FURNACE.

APPLICATION FILED JAN. 29. 1917.

. Patented D96 jzvezr/ IZ07YZQJL% T. A. MARSH FURNACE.

APPLICATION FILED 1AN.29. 191

Patented Dec. 30, 1919.

2 SHEETS-SHEET 2.

UNITED STATES PATENT THOMAS A. MARSH, OF CHICAGO, ILLINOIS, ASSIGNQB T0 GREEN ENGINEERING COM- PANY, OF EAST CHICAGO, INDIANA, A CORPORATION OF ILLINOIS.

FURNACE. 0

Specification of Letters Patent.

Patented Dec. 3d, iltlil Application filed January 29, 1917. Serial No. 1 15,2M.

Improvements in Furnaces, of which the following is a specification,

This invention relates to improved features of construction for furnaces, and more in particular of furnaces of the mechanical stoker type, whereby access may be more readily had to the grate, for the purpose of inspection or cleaning or for the making of adjustments of certain regulating devices located within the combustion chamber.

Furnaces of the mechanical stoker type are ordinarily constructed in such a manner that the combustion chamber is not capable of access from the front of the furnace, because of the presence of the fuel feeding and grate actuating devices, hence the control of the conditions within the furnace is largely dependent upon the regulation of said devices. In practice, however, proper conditions of combustion cannot be always secured, and it is frequently necessary to correct faulty conditions by the manual application of tools, as, for instance for breaking up or removal of clinker formations, or otherwise treating portions of the fuel bed. Inasmuch as the combustion chamber cannot be reached from the front of the furnace, it is proposed to provide a construction such that the grate may be reached, by the provision of a compartment directly behind the combustion chamber, capable of entrance by a person and having a movable partition or door, which may be opened when it is desired to inspect or attend to the fire while the furnace is in operation.

A further feature of the invention is the provision of an adjustable device operable .-from the rear of the combustion chamber and serving as a gate or retarding member to control the discharge of the ash from the grate, and further to normally seal the space at the rear of the grate, but capable of being opened to permit access to the fuel bed for the purpose of inspection, the insertion of tools, or removal of clinker formations.

A desirable construction for a furnace embracing the features of the invention is hereinafter more fully described in connection with the wherein- Figure 1 is a view in vertical section of accompanying drawings,

.the rear portion of the combustion chamber of a furnace, and showing the features embodying the invention;

Fig. 2 is a View in horizontal section takenon line 2-2 of Fig. 1; and

Fig. 3 is a detail view in vertical section taken on line 3 of Fig. 1, showing the waterback and gate member in elevation.

rear ends thereof, there being provided suitable actuating mechanism for moving the grate. As illustrated in the drawings, the rear portion of the grate 10 is shown, the same being mounted on the rear sprocket wheels 12, carried upon a transverse shaft extending transversely below the cross-wall 14: and beams 15 and mounted at their ends,, The lower in the side walls of the furnace. cross-beams 16 are'preferably arranged by locating one I-beain at the rear ends of the upper longitudinal beams 15 and a pair of such beams 16 located in closely spaced relation intermediate the ends of said upper beams 15. Immediately to the rear of the cross-wall 14 is a portion of the water tube boiler of the furnace, namely, the lower drum 17, the remaining part of the boiler occupying the space above the combustion chamber and throughout the length of the furnace. Immediately below the drum 17 and extending rearwardly from the rearmost cross-beam 16, is a horizontal part1- tion wall 18, serving to separate the space therebelow from the space above, wherein is located the boiler. This horizontal wall extends rearwardly to a vertical wall 19 of brick, which may be the rear wall of the furnace or av separate wall spaced inwardly therefrom and resting upon the foundation of the furnace. Immediately below the rearmost cross-beams 16 and adjacent the forward end of the horizontal wall 18, is a vertical partition wall 20 provided with doors, as will hereinafter be pointed out, said partition wall extending from the under surface of the forward end of the horizontal partition wall downwardly below the grate and terminating just above the fioor 21 of the furnace and supported upon a short vertical wall 22 rojecting upwardly from the foundation. s a preferable construction, the vertical partition wall20 consists of a rectangular frame 23, made up of angle-members supported in the surrounding walls and a central vertical wall section 24 dividing the frame 23 into'two openings at either side thereof. Hinged to outer vertical frame members are two metal doors 25, 25, adapted to close the openings in the partition wall and arranged to swing rearwardly on suitable vertically arranged hinges 26, there being provided suitable. latches or catches 27 on the adacent edges of the doors and the central section 24 for locking the doors in closed position.

It is manifest that the horizontal wall 18. the rear wall 19, and the partition wall 20, inclose a space which forms a chamber or compartment located in close proximity to the rear of the combustion chamber, and of suflieient size to permit a person to stand erect therein and to work with freedom. An entrance or door 28 is provided in the side wall 9, permitting access to the chamber from the exterior of the furnace. By means of this chamber a man mayenter the interior of the furnace immediately behind the combustion chamber, and, by opening one or both of the doors 25, 25, is enabled to inspect the grate, to attend the fuel bed, or make adjustments of the devices hereinafter described. 7

Referring now to the adjustable gate member and associated parts, there is provided immediately below the front margin of the cross-wall 14 a water-back, comprising two water-circulating tubes 29 and 30, extending transversely of the combustion chamber above the grate and arranged vertically one above the other, the upper tube 29 being located adjacent to the under surface of the cross-wall and preferably in conmas er tact with the longitudinal supporting beams 15, and the lower tube 30 located vertically below the upper tube and spaced a short distance therefrom and,substantially midway between the surface of'the grate and the under surface of the cross-wall. The water-back of tubular formation primarily serves as a retarding member, extending above the grate and defining the opening for the discharge of ashes from the grate, the same being preferably water cooled to prevent the adhesion of clinkers thereto, thus keeping the discharge opening free from accumulation of clinkers. Immediately behind the upper t'ube 29 is mounted a transverse baflle plate 31, secured to the beams 15 and comprising a substantially T-shaped member, depending from the under surface of the beams 15, below the upper tube, and inclined forwardly toward the lower tube, the lower margin of the baffle plate 31 having contact along the upper surface of said lower tube, thereby closing or sealing the space between the tubes.

Pivotally mounted within the space to the rear and above the grate, are the adjustable gates or retarding members 32, 32, comprising vertically arranged lates extending transversely of the grate between the side walls of the furnace and located immediately behind the tubes 29 and 30 and below the fixed plate 31, As a preferable construction, the gate members consist of two sections, each extending throughout one-half of the width of the grate and each supported and operating independently of the other.

The plates 32, 32 are movably mounted, as

of horizontal arms 33, 33 attached to the rear surfaces of the plates, each plate being provided with two arms at the ends thereof. The arms extend rearwardly and are rigidly mounted upon, or keyed to, rotatable shafts 34, 34, each shaft extending throughout the length of its associated plate'and in axial alinement with each other. The shafts 34, 34 are journaled in bearings 35 secured be tween the lower flanges of the forward pair of cross-beams 16, 16 and midway between the ends of the beams 15. The bearings 35 are preferably three in number, one at the outer ends of each shaft and a central hearing supporting the adjacent ends of each shaft. The arms 33 are preferably of V- form, thereby providing the divergent arms extending from the pivotal point and joined to the plates adjacent to their upper and lower margins, by means of bolts or con- J30 manner.

necting members 36. The plates 32 are, by this manner of mounting, free to be rotated about the axis of the shafts, the plates being preferably curved transversely and in the arc of a circle taken about the axis of rotation of the shafts 34, 34.

As a means for operating the gate mem I bers, the following construction is employed: One arm of each plate, preferably the arms adjacent the side walls of the furnace, is provided with a rearwardly extending boss 37, in which is rigidly secured an operating lever 38, terminating adjacent the I rear doors 25, 25 of the partition wall 20'. Mounted upon the side wall of the furnace and adjacent to each of the levers 38, 38,

is provided a quadrant 39, arranged vertically and adjacent the plane of the move-- ment of the levers. The quadrants 39, 39 are provided throughout their lengths with a series of apertures 40, located between the margins thereof and spaced suitable distances apart. The purpose of the quadrants is to provide means for holding the gate members in any desired position of adjustment, this being accomplished by the pro vision of a pin or stop member 41, adapted to be inserted in one of the apertures 4-0 and engaging the levers to prevent the upward swinging movement thereof.

hen the furnace is in operation, the normal position of thegate member is below the lower tube 30, wit-Hits lower margin spaced a predetermined distance above the surface of the grate, thereby defining the size of the discharge opening for the ashes,

- as well as serving as a retarding member to retain the layer of fuel above the discharge opening within the combustion chamber until it has been fully consumed and reduced to ash. The space above the gate is closed by the tubes 29 and 30 and the fixed plate 31,, said members serving also to re tard the upper layer of fuel, and also act ing, in conjunction with the gate members, to seal the space between the grate and the cross-wall and above the discharge opening.-

To operate one or both of the gate members, a person enters the rear chamber and, opening the doors, can manipulate the operating levers and thus swing the gate members, either to vary the size of the discharge opening, or completely open the space, by rotating the same upwardly to their fullest extent. The gate members being removed from such space, free access may be had to the fuel bed at the rear of the grate, either for the purpose of inspection or for the introduction of tools for the purpose of cleanmg.

'The purpose of the compartment located at the rear of the combustion chamber is now evident, namely, that it permits a per son to approach in close proximity to the grate while the furnace is in operation. and,

" which otherwise could not pass through the discharge opening.

. The constructing of the gate members in two or more sections, rather than a single section, is advantageous in that it permits one portion of the grate to be inspected and cleaned without disturbing the remaining portion of the grate, thereby avoiding the loss of unburned fuel that would be discharged from the portion not requiring attention. d

In brief, the features embodied in ,the furnace hereindescribed make it possible to give the fuel bed the required attention, in spite of the'inaccessibility of the combustion chamber from the front of the furnace, as is the case in most furnaces of the mechanlcal Stoker type, thereby greatly increasing the possibility of efficient and proper handling and operation of furnaces so equipped.

I claim as my invention:

1. In a furnace, the combination of a com bustion chamber, a grate mounted in said combustion chamber, a compartment formed at the rear of the furnace and communicat- 1ng with said combustion chamber, and a fuel-retarding member adjustably mounted above the rear end of the grate and operative from said compartment.

2. In a furnace, the combination of a combustion chamber, a grate mounted in said combustion chamber, a compartment at the rear of said combustion chamber, a vertical partition wall separating said combustion chamber and said compartment and pro-- vided with an opening therein, a closure for said opening, and a fuel-retarding member adjustably mounted above the rear end of the grate and capableof access from said compartment through the opening in said partition wall.

3. In a furnace, the combination of a combustion chamber, a grate therein, a fuel retarding plate adjustably mounted above the grate adjacent the rear end thereof, and comprising arms connected with said plate and having pivotal connection with fixed parts of the furnace structure at a point to effect the movement of said plate in a path at right-angles to the surface of said}, grate, and means for retaining said plate in" any of its adjusted positions.

In a furnace, the combination of a combustion chamber, a grate therein, a fuel re-. tarding member comprising a plate adjustably mounted above the grate adjacent the rear end thereof and adapted to move in a path at right-angles to the surface of said grate, arms extending rearward from said plate and having pivotal connection with fixed parts of the furnace structure, and means for engaging said arms for bold ing said plate in any of its adjusted positions.

5. In a furnace. the combination of a combustion chan'iber. a grate mounted in said combustion chamber, a partition wall spaced rearwardly from said grate, a door in said partition wall, a cross-wall extending over the rear end of said grate, an adjustable fuel-retarding member pivotally mounted intermediate the grate and said partition wall and comprising a gate member vertically adjustable above the rear end of said grate. and operating means adjacent said vertical partition wall, the same being op erable through the doorway in said partition wall.

o. In a furnace, the combination of a combustion chamber, a grate mounted in said combustion chamber, a compartment spaced rearwardly from said grate provided With a door communicating with the combustion chamber, a cross-Wall extending over the rear end of said "grate, a fixed fuel-retard,-

ing member depending from said cross-wail, and a gate member adapted to open and close the space below said fixed fuel-retarding member and capable of adjustment through the doorway in said compartn'ient. 3e

7. In a furnace, the combination of a grate mounted in the combustion chamber of the furnace, at compartment at the rear of said combustion chamber adapted to be entered from the exterior of the furnace and embracing a wall separating the combustion chamber therefron'i, a door in said Wall, a

fuel-retarding member pivotally mounted above the rear end of said grate, and an operating lever adjacent said door and op- 40 crable thcrethroug'h from said compartment.

THOMAS A. MARSH.

\Vitnesses H. R. VILSON A. S. BRADY. 

